Early versions were mainly designed with two levels.

VOA: special.2009.12.29

India,for example, has promised to cut emissions by at least twenty percent from two thousand five levels by two thousand twenty.

VOA: special.2009.12.26

The agreement sets targets to prevent the Earth's average temperature from rising more than two degrees Celsius above pre-industrial levels.

VOA: special.2009.12.26

All agreed that global temperatures should not rise by more than an average of two degrees Celsius above pre-industrial levels.

VOA: special.2009.07.11

The team found levels of lead as high as thirty-two thousand parts per million in tests on some paint samples from Ecuador.

VOA: special.2009.08.31

His team found that levels of stress were highest among adults between the ages of twenty-two and twenty-five.

VOA: special.2010.08.03

Scientists say it formed when high sea levels flooded the middle of North America, splitting the continent in two for millions of years during the late Cretaceous period.

VOA: special.2010.10.05

Two genes are responsible for Shh levels.

VOA: special.2009.12.22

Indian Kashmir has been wracked by a two-decade-long separatist insurgency, although levels of violence have sharply dropped in the lpast five years.

VOA: standard.2009.10.28